The study investigates the relationship between soil pH and nitrous oxide (N₂O) emissions, a potent greenhouse gas. Through global meta-analyses and field experiments, the authors find that soil pH predominantly controls N₂O emission factors (EFs) by affecting the composition of denitrifying microorganisms. The highest EFs occur in moderately acidic soils (pH 5.6–6.5), where N₂O-producing microorganisms dominate over N₂O-consuming ones, leading to increased N₂O emissions. The results challenge the prevailing understanding of N₂O EFs, suggesting that soil pH has a unimodal relationship with N₂O emissions, with the highest emissions at moderate acidity. The findings highlight the need for alternative strategies to mitigate N₂O emissions, such as manipulating the community composition and activities of N₂O-producing and consuming microbes.The study investigates the relationship between soil pH and nitrous oxide (N₂O) emissions, a potent greenhouse gas. Through global meta-analyses and field experiments, the authors find that soil pH predominantly controls N₂O emission factors (EFs) by affecting the composition of denitrifying microorganisms. The highest EFs occur in moderately acidic soils (pH 5.6–6.5), where N₂O-producing microorganisms dominate over N₂O-consuming ones, leading to increased N₂O emissions. The results challenge the prevailing understanding of N₂O EFs, suggesting that soil pH has a unimodal relationship with N₂O emissions, with the highest emissions at moderate acidity. The findings highlight the need for alternative strategies to mitigate N₂O emissions, such as manipulating the community composition and activities of N₂O-producing and consuming microbes.